The present invention relates to a process cartridge and a photosensitive member cartridge configured to be mounted to an electrophotographic image forming apparatus.
An image forming apparatus has been known in which a developing cartridge including a developing roller is mounted to a drum cartridge including a photosensitive drum, which are then detachably mounted to an apparatus main body of the image forming apparatus, as a process cartridge.
For example, the drum cartridge of the process cartridge includes a developing cartridge mounting part for mounting the developing cartridge and a lock member for suppressing separation of the mounted developing cartridge. When mounting the developing cartridge to the drum cartridge, the developing cartridge is first positioned above the drum cartridge. Then, the developing cartridge is moved downwards to mount the developing cartridge to the developing cartridge mounting part of the drum cartridge. At this time, the lock member is engaged to a boss of the developing cartridge from above, so that the separation of the developing cartridge from the drum cartridge is suppressed. Then, the process cartridge is mounted to a main body casing of a laser printer.
According to the related process cartridge, when mounting the developing cartridge to the drum cartridge, the developing cartridge may be imperfectly mounted to the developing cartridge mounting part of the drum cartridge. When the process cartridge is mounted to the main body casing at this state, an image forming operation cannot be performed.